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The evolution of brittle fracture in rocks
3A
18. EISAMNY,MK FLETCH~, EB Evaluation of elasticity of clay soils - by M.K. Elsanmy - published In Can.Geotech.J° VIO,No.4, 1973. Discussion of paper by E.B. Fletcher, and authors reply. IF,4R. CAN. GEOTECH. J .Vll,N3, AUG. 1974, P438- 440. The original paper is a mathematical evaluation of the elasticity of clay soils. Fletcher comaents on some of the equations in the original paper and queries their validity.
Texture,structure,composition and density See also abstracts:
51,101.
19. BARON,LI Hardness coefficients of rocks° Textbook. NAUKA, ~DSCOW, 1972. In this book man~ years of research and observation by the author are sunmmrlzed and the question of estimating the engineering properties of rocks is exhaustively discussed. Five of the seven chapters deal with a careful analysis of methods of determining hardness coefficients on physical models and from data from field processes, 20.
HANSAG I, I A method of determining the degree of fissuration of rock. 5F,9T,19R. INT .J.ROCK MECH.MIN. SCI .VII,NIO,OCT. 197h, P379-388. 21. STATHAM, I UNIV .BRISTOL, GB The relationship of porosity and angle of repose to mixture proportions in assemblages of different sized materlals. Figs~Tabls,Refs. SEDIMENTOIOGY, V21, NI, 197~, P149-162. Rotating drum experiments on the repose angles of mixtures of glass spheres have shown that the angle of shear is strongly influenced by the proportions of the mixture° It was found that the angle of shear reached a peak value for the minimum porosity mixture, where the pore spaces between the large particles were Just filled with small material, which was attributed to increased dilatation on the shear plane during avalanching. The geomorphic significance of these observations, in terms of slope development, is discussed° Auth. 22. ASTM Evaluation of relative density and its role in geotechnical projects involving cohesionless soils° ASTM PUBLICATION STP 523,CODE N0.04-523000-38, 1973,504P. This volume includes thirty-one papers dealing with the determination of density considering the measurement of maxlnmm, minimum and in-situ density; correlat. ion between relative density and measured performance of properties and granular soils; and use of relative density in geotechnical projects. 23. SWANSON,HE MCMURDIE, HF MORE IS, MC Standard X-ray diffraction powder patterns .-70 substances are analysed, 52 represent experimental data and 18 are calculated. US. NAT. BUR. STAND .MDNOGRAPH. SECT. ll, N25,1974,134P.
the magnetic anisotropy of deformed rocks. 9F,22R. TECTONOPHYSICS, V24,NI-2,1974, PII5-131.
Fracture processes in rocks 25. DI~0U, SG THIRUMALAI,K Thermal expansion behaviour of intact and thermally fractured mine rocks. Figs,Refs. PROC. AM. INST. PHYS. NI7,1974, P60- 71 • A report is given of a study during which a method of predicting the damage induced b y temperature variations from the thermal dilation characteristics of fractured and intact mine rocks was formulated and tested. A dilatometer system capable of controlled heating and cooling rates w~s designed and used for the measurement.
26. GIARDIN, A~ UNIV .GEORGIA, ATHOS, USA A review of rock behaviour to shear over approximately 100 kbar of confining pressure and a speculative model for seismic disturbances. IIF,4T,27R. J .GEOPHYS .RES .V79,N8,1974, Pi183-1195. Recent high-pressure room-temperature torsional shear data on granodlorite, granite, quartz-biotite-plagioclase gneiss, and dunite are reviewed. A direct proportionality was observed during torsional tests between the magnitude of stress drop at failure and the volume of rock undergoing failure. Two mechanisms are proposed for shear displacement beyond the limit of simple frictional sliding and a previously proposed failure model is revised on the basis of new data on room-temperature strengths and observed microstructural changes, available data on strengths at high temperatures and pressures, t h e temperature profile within a cbwnmovIng crustal slab, and the spatial distribution of earthquakes within such a slab.
27. LAJJAI, EZ LAJTAI, VN FARRAR, NS The evolution of brittle fracture in rocks.-Also a discussion of the paper by E.Z. LaJtai and V.N. Lajtai, by N.S. Farrar, and a reply by the authors. 7F. J. GEO L. SO C. LOND. V130, N1,1974, P1-18. This paper concentrates on the process of fracture occuring under compressive loading. The problem is considered in two main sections: a microscopic view of fracture, and a preliminary view of brittle fracture in the nmcroscopic scale. A number of conclusions reached in this paper are based on experimental work using plaster of paris as a model material in the microscopic scale and as a natural material in the macroscopic scale.
28. AND~SON, TB QUEENS UNIV .BELFAST, GB The relationship between kink.bands and shear fractures in the experimental deformation of slate. 10F, 28R. J .GEOL. SOC .IOND .V130,N4,1974, P367-382. This paper describes a series of experiments on slate, at confining pressures up to 7.24 kb. The results establish distinct and separate failure criteria for kink-bands and shear fractures in the experimental material and also suggest that the authors of both the fixed.length segment and kink-plane migration hypotheses may be correct in that kink-band deformation develops differently at different confining pressures o Auth.
29. 24. OWENS, WH UN IV.BIRMINGHAM, GB Mathematical model studies on fracture affecting
BATDORF, SB Weibull statistics for polyaxial stress states.-Note.4R. J. AMER .CERAMIC SOC .V57,NI, 1974, P44-45.
18. EISAMNY,MK FLETCH~, EB Evaluation of elasticity of clay soils - by M.K. Elsanmy - published In Can.Geotech.J° VIO,No.4, 1973. Discussion of paper by E.B. Fletcher, and authors reply. IF,4R. CAN. GEOTECH. J .Vll,N3, AUG. 1974, P438- 440. The original paper is a mathematical evaluation of the elasticity of clay soils. Fletcher comaents on some of the equations in the original paper and queries their validity.
Texture,structure,composition and density See also abstracts:
51,101.
19. BARON,LI Hardness coefficients of rocks° Textbook. NAUKA, ~DSCOW, 1972. In this book man~ years of research and observation by the author are sunmmrlzed and the question of estimating the engineering properties of rocks is exhaustively discussed. Five of the seven chapters deal with a careful analysis of methods of determining hardness coefficients on physical models and from data from field processes, 20.
HANSAG I, I A method of determining the degree of fissuration of rock. 5F,9T,19R. INT .J.ROCK MECH.MIN. SCI .VII,NIO,OCT. 197h, P379-388. 21. STATHAM, I UNIV .BRISTOL, GB The relationship of porosity and angle of repose to mixture proportions in assemblages of different sized materlals. Figs~Tabls,Refs. SEDIMENTOIOGY, V21, NI, 197~, P149-162. Rotating drum experiments on the repose angles of mixtures of glass spheres have shown that the angle of shear is strongly influenced by the proportions of the mixture° It was found that the angle of shear reached a peak value for the minimum porosity mixture, where the pore spaces between the large particles were Just filled with small material, which was attributed to increased dilatation on the shear plane during avalanching. The geomorphic significance of these observations, in terms of slope development, is discussed° Auth. 22. ASTM Evaluation of relative density and its role in geotechnical projects involving cohesionless soils° ASTM PUBLICATION STP 523,CODE N0.04-523000-38, 1973,504P. This volume includes thirty-one papers dealing with the determination of density considering the measurement of maxlnmm, minimum and in-situ density; correlat. ion between relative density and measured performance of properties and granular soils; and use of relative density in geotechnical projects. 23. SWANSON,HE MCMURDIE, HF MORE IS, MC Standard X-ray diffraction powder patterns .-70 substances are analysed, 52 represent experimental data and 18 are calculated. US. NAT. BUR. STAND .MDNOGRAPH. SECT. ll, N25,1974,134P.
the magnetic anisotropy of deformed rocks. 9F,22R. TECTONOPHYSICS, V24,NI-2,1974, PII5-131.
Fracture processes in rocks 25. DI~0U, SG THIRUMALAI,K Thermal expansion behaviour of intact and thermally fractured mine rocks. Figs,Refs. PROC. AM. INST. PHYS. NI7,1974, P60- 71 • A report is given of a study during which a method of predicting the damage induced b y temperature variations from the thermal dilation characteristics of fractured and intact mine rocks was formulated and tested. A dilatometer system capable of controlled heating and cooling rates w~s designed and used for the measurement.
26. GIARDIN, A~ UNIV .GEORGIA, ATHOS, USA A review of rock behaviour to shear over approximately 100 kbar of confining pressure and a speculative model for seismic disturbances. IIF,4T,27R. J .GEOPHYS .RES .V79,N8,1974, Pi183-1195. Recent high-pressure room-temperature torsional shear data on granodlorite, granite, quartz-biotite-plagioclase gneiss, and dunite are reviewed. A direct proportionality was observed during torsional tests between the magnitude of stress drop at failure and the volume of rock undergoing failure. Two mechanisms are proposed for shear displacement beyond the limit of simple frictional sliding and a previously proposed failure model is revised on the basis of new data on room-temperature strengths and observed microstructural changes, available data on strengths at high temperatures and pressures, t h e temperature profile within a cbwnmovIng crustal slab, and the spatial distribution of earthquakes within such a slab.
27. LAJJAI, EZ LAJTAI, VN FARRAR, NS The evolution of brittle fracture in rocks.-Also a discussion of the paper by E.Z. LaJtai and V.N. Lajtai, by N.S. Farrar, and a reply by the authors. 7F. J. GEO L. SO C. LOND. V130, N1,1974, P1-18. This paper concentrates on the process of fracture occuring under compressive loading. The problem is considered in two main sections: a microscopic view of fracture, and a preliminary view of brittle fracture in the nmcroscopic scale. A number of conclusions reached in this paper are based on experimental work using plaster of paris as a model material in the microscopic scale and as a natural material in the macroscopic scale.
28. AND~SON, TB QUEENS UNIV .BELFAST, GB The relationship between kink.bands and shear fractures in the experimental deformation of slate. 10F, 28R. J .GEOL. SOC .IOND .V130,N4,1974, P367-382. This paper describes a series of experiments on slate, at confining pressures up to 7.24 kb. The results establish distinct and separate failure criteria for kink-bands and shear fractures in the experimental material and also suggest that the authors of both the fixed.length segment and kink-plane migration hypotheses may be correct in that kink-band deformation develops differently at different confining pressures o Auth.
29. 24. OWENS, WH UN IV.BIRMINGHAM, GB Mathematical model studies on fracture affecting
BATDORF, SB Weibull statistics for polyaxial stress states.-Note.4R. J. AMER .CERAMIC SOC .V57,NI, 1974, P44-45.